Abstract
Extensive lesions of the frontal lobes are followed by pronounced personality changes. This has been shown beyond doubt by the effect of neuro-surgery performed for the removal of brain tumours or for the relief of mental illness. To identify such changes and the lesions responsible for them at least four conditions seem necessary: (a) Knowledge of the limits, variations and connections of the main pre-frontal areas.—In this field the researches of Professor Alfred Meyer and his associates, Mrs. Beck and T. McLardy, are of primary importance (1950).